Spectral signature

Imagine you have a bunch of crayons that you use to draw pictures. Some of the crayons are red, some are green, and some are blue. When you draw a picture with these crayons, you can see the different colors that you used. Each color has a different "signature" or "mark" that makes it unique.

Just like crayons have colors that make them unique, every material on Earth (like grass, rocks, and water) has a special signature that helps us tell it apart from other materials. Scientists can use special tools to measure these signatures, called "spectral signatures".

These tools measure different types of light that bounce off of the material, kind of like how your eyes see light bouncing off crayons. But instead of just seeing colors, scientists can use these tools to measure how much light is being reflected and at what wavelengths (sort of like the different colored marks on your crayons).

By looking at the spectral signature of a material, scientists can tell what it's made of and even get clues about things like how healthy a plant is or what kind of minerals might be in a rock. So just like how you can tell what colors you used to draw a picture, scientists can tell what materials are present by looking at their spectral signature.